Rust 1.85 lints (#7019)

N/A


  2 changes:
1. Replace Option::map_or(true, ...) with is_none_or(...)
2. Remove unnecessary `Into::into` blocks where the type conversion is apparent from the types

common/account_utils/src/validator_definitions.rs

@@ -115,7 +115,6 @@ impl SigningDefinition {
                 voting_keystore_password_path: Some(path),
                 ..
             } => read_password_string(path)
-                .map(Into::into)
                 .map(Option::Some)
                 .map_err(Error::UnableToReadKeystorePassword),
             SigningDefinition::LocalKeystore { .. } => Err(Error::KeystoreWithoutPassword),